Hydrochloric Acid → (2S,4S)-N-methanesulfonyl-4-diphenylphosphinyl-2-hydroxymethylpyrrolidine

Participants

Reaction Conditions

Reaction Steps

In 180 ml of methanol was dissolved 8.39 g (0.0176 mol) of 2S,4S)-N-methanesulfonyl-2 -tert-butyldimethlysilyloxymethyl-4-di-phosphinopyrrolidine [VI], and 11.85 g (0.0348 mol) of 10% hydrogen peroxide was added dropwise to the solution under ice-cooling. The mixture was stirred at 0° C. for one hour and then at room temperature for one hour. To the mixture was then slowly added dropwise a liquid mixture of 8.6 g of 35% hydrochloric acid, 52.7 g of water and 38.7 g of methanol, and the mixture was stirred for 2 hours at room temperature. Any insoluble matter was removed from the mixture by filtration and the filtrate was concentrated under reduced pressure. The concentrate was dissolved in 50 ml of water and the aqueous solution was extracted three times with 100 ml of methylene chloride in each case. The extract was washed with a saturated solution of sodium hydrogen carbonate, dried over magnesium sulfate and concentrated under reduced pressure whereby white crystals were obtained which were then recrystallized from a mixture of ethanol and isopropyl alcohol. Yield 5.3 g (80%), melting point: 138°-139° C.

Provenance & Evidence